Genetic impact of Neopyropia yezoensis cultivation on wild populations: a case study on the typical laver culture areas in China by SSR analysis

Abstract

Neopyropia yezoensis is a typical intertidal seaweed and a major mariculture crops in China. The culture area of N. yezoensis has been largely increasing in the past decade. Whether large-scale cultivation of N. yezoensis has a genetic impact on wild populations remains unknown. Here, eleven polymorphic microsatellite markers were developed and applied for the genetic structure analysis of 22 N. yezoensis populations from along the coast of China. The populations were divided into 4 groups based on the Bayesian model-based structure analysis. A significant genetic structure difference was present between the cultivated populations and the wild ones. The 13 wild populations were divided into two distinct groups, with no obvious correlation between the inter-population genetic variation and geographical distance within each group. The average polymorphism of 9 cultured N. yezoensis populations was higher than that of the wild populations, and the percentage of polymorphic loci of the most cultivated populations was at a high level (P=90.91%). It indicated that the germplasm of cultivated N. yezoensis in China are diversified. The genetic differentiation between the cultivated populations and the wild populations decreased with the increasing cultivation time. But the gene flow between the cultivated populations and the wild ones was asymmetric, exhibiting a trend from wild population to cultured population. The result indicated that even if there is a genetic impact of N. yezoensis aquaculture on wild resource, it is a long-term and slow process. This research provided useful insights for future germplasm resource evaluation and genetic breeding of N. yezoensis.